Article of footwear with fluid-filled chamber lacking an inflation channel and method for making the same

ABSTRACT

An article of footwear is provided having a pressurized fluid-filled chamber in the sole structure having a continuous perimeter weld and lacking an inflation channel. The chamber may be formed from opposing polymer sheets, a continuous perimeter weld lacking a weld channel bonding the sheets and forming an interior void between the sheets, and a fluid disposed within the interior void exerting outward pressure on the sheets. A method for making the chamber can include placing a pair of polymer sheets in an opposing arrangement, pressing opposing perimeter weld portions of the sheets against each other to form an airtight seal along a perimeter region of an interior void, supplying a flow of pressurized air between the opposing sheets into the interior void, and, while maintaining a desired fluid pressure, welding the perimeter weld portions of the sheets to each other. A high-frequency welder for forming chamber is also provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of U.S. patent application Ser. No.13/722,153, filed Dec. 20, 2012, the entire contents of which are herebyincorporated by reference.

BACKGROUND

Conventional articles of athletic footwear include two primary elements:an upper and a sole structure. The upper is generally formed from aplurality of elements (e.g., textiles, foam, leather, synthetic leather)that are stitched or adhesively bonded together to form an interior voidfor securely and comfortably receiving a foot. The sole structure issecured to a lower portion of the upper and is generally positionedbetween the foot and the ground. In addition to attenuating groundreaction forces (i.e., providing cushioning) during walking, running,and other ambulatory activities, the sole structure can influence footmotions (e.g., by resisting pronation), impart stability, and providetraction, for example. Accordingly, the upper and the sole structureoperate cooperatively to provide a comfortable structure that is suitedfor a wide variety of athletic activities.

The sole structure incorporates multiple layers that are conventionallyreferred to as a sockliner, a midsole, and an outsole. The sockliner isa thin, compressible member located within the void of the upper andadjacent to a plantar (i.e., lower) surface of the foot to enhancecomfort. The midsole is secured to the upper and forms a middle layer ofthe sole structure that attenuates ground reaction forces duringwalking, running, or other ambulatory activities. The outsole forms aground-contacting element of the footwear and is usually fashioned froma durable and wear-resistant rubber material that includes texturing toimpart traction.

The primary material forming many conventional midsoles is a polymerfoam, such as polyurethane or ethylvinylacetate. In some articles offootwear, the midsole can also incorporate one or more thin plates toreinforce the midsole. In some articles of footwear, the midsole canfurther incorporate a sealed and fluid-filled chamber that increases thedurability of the footwear and enhances ground reaction forceattenuation of the sole structure. The fluid-filled chamber can be atleast partially encapsulated within the polymer foam, as in U.S. Pat.No. 5,755,001 to Potter, et al., U.S. Pat. No. 6,837,951 to Rapaport,and U.S. Pat. No. 7,132,032 to Tawney, et al.

In other footwear configurations, the fluid-filled chamber cansubstantially replace the polymer foam, as in U.S. Pat. No. 7,086,180 toDojan, et al. In general, the fluid-filled chambers are formed from anelastomeric polymer material that is sealed and pressurized, but canalso be substantially unpressurized. In some configurations, textile orfoam tensile members can be located within the chamber or reinforcingstructures can be bonded to an exterior surface of the chamber to impartshape to or retain an intended shape of the chamber.

SUMMARY

An article of footwear having a pressurized fluid-filled chamberincorporated in the sole structure that lacks an inflation channel canprovide various advantageous features, such as a uniform perimeter weld,improved integration with the sole structure and efficientmanufacturability of the fluid-filled chamber. Many of theseadvantageous features can be enhanced, and additional advantageousfeatures provided, through various options such as the use of monolayerfilms or multi-layer coextruded films and differing arrangementsincluding fluid types, fluid pressures and chamber configurations.

In one configuration, an article of footwear has an upper and a solestructure secured to the upper and having a midsole, an outsole, and afluid-filled chamber embedded within the midsole. The fluid-filledchamber can include a first flexible polymer sheet, a second flexiblepolymer sheet, a continuous perimeter weld lacking an inflation channelbonding the sheets and forming an interior void between the sheets, anda fluid disposed within the interior void exerting outward pressure onthe sheets. The continuous perimeter weld can have a continuouscross-sectional area along its length. The fluid-filled chamber can alsoinclude a gate region through which fluid flows to fill the chamber whenforming the chamber, and that is integrated in the perimeter weld afterthe chamber is filled and while welding the sheets to each other.

A method for making a fluid-filled chamber having a continuous perimeterweld and lacking an inflation channel can include placing a pair ofpolymer sheets in an opposing arrangement, pressing opposing perimeterweld portions of the sheets against each other to form an airtight sealalong a perimeter region of an interior void, supplying a flow of fluidbetween the opposing sheets into the interior void to provide a fluidpressure, and, while maintaining the fluid pressure, welding theperimeter weld portions of the sheets to each other to form anuninterrupted perimeter weld around the chamber lacking an inflationchannel. The method can further include unsealing an inflation region ofthe perimeter weld portions of the sheets to permit the fluid flowthrough an inflation gap in the inflation region formed between thesheets leading into the interior void.

A high-frequency welder apparatus for forming a fluid-filled chamberlacking an inflation channel in a single stage can include a cavity weldstructure having a cavity surface formed therein including a cavityraised perimeter weld portion and a cavity recessed central portiondisposed within the cavity raised perimeter weld portion, a core weldstructure opposing the cavity weld structure having a core surfaceincluding a core perimeter weld portion and a core central portiondisposed within the core perimeter weld portion, and a movable gatevalve disposed proximate the perimeter weld portion on one of the cavityand core weld structures. The movable gate valve can be configured towithdraw a gate region of the perimeter weld portion surface on the oneof the cavity and core weld structures selectively between an open andclosed position to permit a temporary inflation channel to form betweenthe first and second polymer sheets during an inflation and weldingprocess. One of the cavity and core weld structures can be movable tomove the cavity and core weld structures selectively toward and awayfrom each other, and the cavity and core weld structures can each beconfigured to receive a polymer sheet on the cavity and core surfaces,press portions of the polymer sheets on the cavity and core raisedperimeter weld portions against each other, and weld portions of thepolymer sheet on the cavity and core raised perimeter weld portions toeach other while a cavity formed between the sheets proximate the cavityand core central portions contains a pressurized fluid.

Advantages and features of novelty characterizing aspects of theinvention are pointed out with particularity in the appended claims. Togain an improved understanding of advantages and features of novelty,however, reference can be made to the following descriptive matter andaccompanying figures that describe and illustrate various configurationsand concepts related to the invention.

FIGURE DESCRIPTIONS

The foregoing Summary and the following Detailed Description will bebetter understood when read in conjunction with the accompanyingfigures.

FIG. 1 is a lateral side view of an article of footwear having a solestructure that includes a fluid-filled chamber lacking an inflationchannel.

FIG. 2 is medial side view of the article of footwear of FIG. 1.

FIG. 3 is a perspective view of an example configuration of afluid-filled chamber having a continuous perimeter weld and lacking aninflation channel.

FIG. 4 is a side view of the fluid-filled chamber of FIG. 3.

FIG. 5 is a top view of the fluid-filled chamber of FIG. 3.

FIG. 6 is a bottom view of the fluid-filled chamber of FIG. 3.

FIG. 7 is a cross-sectional view of the fluid-filled chamber of FIG. 3taken along Line 7-7 shown in FIG. 5.

FIG. 8 is a close view of a cross-section of the perimeter weld of thefluid-filled chamber of FIG. 3 as identified in FIG. 7.

FIG. 9 is a perspective view of a high-frequency welder apparatus forforming a fluid-filled chamber.

FIG. 10 is an elevational cross-sectional view of a portion of thehigh-frequency welder apparatus of FIG. 9 shown in a first positionwhile open with opposing polymer sheets placed therein.

FIG. 11 is an elevational cross-sectional view of the portion of thehigh-frequency welder apparatus of FIG. 9 shown in a second positionwhile closed with a gate valve moving out of a closed position to permitthe inflow of pressurized fluid.

FIG. 12 is an elevational cross-sectional view of the portion of thehigh-frequency welder apparatus of FIG. 9 shown in a third position withthe gate valve in an open position, pressurized fluid flowing through aninflation tube and a temporary inflation channel between the sheets intoan internal chamber between the polymer sheets.

FIG. 13 is an elevational cross-sectional view of the portion of thehigh-frequency welder apparatus of FIG. 9 shown in a fourth positionwith the temporary inflation channel closed and a perimeter weld of thepressurized fluid-filled chamber being formed.

FIG. 14 is an elevational cross-sectional view of the portion of thehigh-frequency welder apparatus of FIG. 9 shown in a fifth position withthe welder apparatus open and a pressurized fluid-filled chamber formedhaving a continuous perimeter weld and lacking an inflation channel.

FIG. 15 illustrates example steps for a method of forming a fluid-filledpressurized chamber lacking an inflation channel, such as thefluid-filled chamber shown in FIG. 3.

FIGS. 16A and 16B show additional example features and steps that can beused with the method of FIG. 15.

FIG. 17 is an elevational cross-sectional view of a portion of anotherconfiguration of a high-frequency welder apparatus for forming apressurized fluid-filled chamber shown in a first position while openwith opposing polymer sheets placed therein.

FIG. 18 is an elevational cross-sectional view of the portion of thehigh-frequency welder apparatus of FIG. 17 shown in a second positionwhile closed with a gate valve moving out of a closed position to permitthe flow of pressurized fluid.

FIG. 19 is an elevational cross-sectional view of the portion of thehigh-frequency welder apparatus of FIG. 17 shown in a third positionwith the gate valve in an open position, pressurized fluid flowingthrough an inflation tube and a temporary inflation channel between thesheets into an interior void between the polymer sheets.

FIG. 20 is an elevational cross-sectional view of the portion of thehigh-frequency welder apparatus of FIG. 17 shown in a fourth positionwith the temporary inflation channel closed and a perimeter weld of thepressurized fluid-filled chamber being formed.

FIG. 21 is an elevational cross-sectional view of the portion of thehigh-frequency welder apparatus of FIG. 17 shown in a fifth positionwith the welder open and a pressurized fluid-filled chamber formedhaving a continuous perimeter weld and lacking an inflation channel.

FIG. 22 is an elevational cross-sectional view of a portion of yetanother configuration of a high-frequency welder apparatus for forming apressurized fluid-filled chamber shown in a first position while openwith opposing polymer sheets placed therein.

FIG. 23 is a perspective view a portion of a lower mold structure of thewelder apparatus of FIG. 22 as indicate by line 23-23 shown in FIG. 22.

FIG. 24 is a perspective view of another example configuration of afluid-filled chamber having a continuous perimeter weld and lacking aninflation channel.

FIG. 25 is a perspective view of another configuration of ahigh-frequency welder apparatus for forming a pressurized fluid-filledchamber.

DETAILED DESCRIPTION

The following discussion and accompanying figures disclose aspects andfeatures pertaining to fluid-filled chambers and methods for makingand/or using the same in the context of configurations of examplefluid-filled chambers. It is understood that the fluid-filled chamberscan be incorporated into various articles and devices, such as articlesof apparel, containers including storage and transportation containers,articles of footwear, etc. and that aspects and features pertaining tothe same can apply to a variety of articles and devices. For example,aspects and features pertaining to fluid-filled chambers and relatedmethods discussed herein can be applicable for articles of apparel, suchas clothing articles or articles of footwear; personal containers suchas backpacks or luggage; sports containers for carrying and/or storingsports equipment, such as golf bags for carrying golf clubs or hockeybags for carrying hockey equipment; articles of footwear; welder devicesand other equipment for forming the fluid-filled chambers; and methodsfor making the same. Example configurations and related conceptspertaining to the fluid-filled chambers are generally disclosed hereinwith reference to example footwear configurations that are suitable forcommon uses including walking, running and general athletic activities.The following discussion and accompanying set of figures (FIGS. 1 and 2)disclose a fluid-filled chamber incorporated in an exemplary article offootwear having a sole structure that includes, for example, a midsoleelement, one or more fluid-filled chambers, and an outsole.

The article of footwear is disclosed as having a general configurationsuitable for running. Concepts associated with the footwear can also beapplied to a variety of other athletic footwear types, includingbaseball shoes, basketball shoes, cross-training shoes, cycling shoes,football shoes, golf shoes, tennis shoes, soccer shoes, walking shoes,and hiking shoes and boots, for example. The concepts can also beapplied to footwear types that are generally considered to benon-athletic, including dress shoes, loafers, sandals, and work boots.Accordingly, the concepts disclosed herein apply to a wide variety offootwear types.

Various features shown in the figures and noted herein may be referredto using directional adjectives such as top, bottom, right, left, up,down, medial, lateral, etc. These descriptions referring to theorientation of the article of footwear or its features as illustrated inthe drawings are for convenience and clarity, and should not beinterpreted as limiting the scope in any way. Generally, however, forconvenience and clarity, articles of footwear and their features aredescribed in the orientation typically encountered when worn by a userstanding on the ground unless otherwise noted. It is understood thatdirectional adjectives will change if the article of footwear and/orrelated features are viewed from a different orientation than aspictured or typically worn by the user.

Footwear Structure

An article of footwear 10 is depicted in FIGS. 1 and 2 as including anupper 20 and a sole structure 30. For reference purposes, footwear 10can be divided into three general regions: a forefoot region 11, amidfoot region 12, and a heel region 13. Forefoot region 11 generallyincludes portions of footwear 10 corresponding with the toes and thejoints connecting the metatarsals with the phalanges. Midfoot region 12generally includes portions of footwear 10 corresponding with an archarea of the foot. Heel region 13 generally corresponds with rearportions of the foot, including the calcaneus bone. Footwear 10 alsoincludes a lateral side 14 and a medial side 15, which extend througheach of regions 11-13 and correspond with opposite sides of footwear 10.More particularly, lateral side 14 corresponds with an outside area ofthe foot (i.e. the surface that faces away from the other foot), andmedial side 15 corresponds with an inside area of the foot (i.e., thesurface that faces toward the other foot). Regions 11-13 and sides 14-15are not intended to demarcate precise areas of footwear 10. Rather,regions 11-13 and sides 14-15 are intended to represent general areas offootwear 10 to aid in the following discussion. In addition to footwear10, regions 11-13 and sides 14-15 can also be applied to upper 20, solestructure 30, and individual elements thereof.

Upper 20 is depicted as having a substantially conventionalconfiguration incorporating a plurality of material elements (e.g.,textiles, foam, leather, and synthetic leather) that are stitched oradhesively bonded together to form an interior void for securely andcomfortably receiving a foot. The material elements can be selected andlocated with respect to upper 20 in order to selectively impartproperties of durability, air-permeability, wear-resistance,flexibility, and comfort, for example. An ankle opening 21 in heelregion 13 can provide access to the interior void. In addition, upper 20can include a lace 22 that is utilized in a conventional manner tomodify the dimensions of the interior void, thereby securing the footwithin the interior void and facilitating entry and removal of the footfrom the interior void. Lace 22 can extend through apertures in upper20, and a tongue portion 23 of upper 20 can extend between the interiorvoid and lace 22. Given that various aspects of the present discussionprimarily relate to sole structure 30, upper 20 can exhibit the generalconfiguration discussed above or the general configuration ofpractically any other conventional or nonconventional upper.Accordingly, the overall structure of upper 20 can vary significantly.

Sole structure 30 is secured to upper 20 and has a configuration thatextends between upper 20 and the ground. In addition to attenuatingground reaction forces (i.e., cushioning the foot), sole structure 30can provide traction, impart stability, and limit various foot motions,such as pronation. The primary elements of sole structure 30 are amidsole element 40, one or more fluid-filled chambers 60, and an outsole70. Each of these elements will be discussed in greater detail below.

Midsole element 40 is secured to a lower area of upper 20 (e.g., throughstitching, adhesive bonding, or thermal bonding) and extends througheach of regions 11-13 and between sides 14 and 15. Portions of midsoleelement 40 are exposed around the periphery of sole structure 30, butcan also be covered by other elements, such as material layers fromupper 20. Midsole element 40 is primarily formed from a foamed polymermaterial, such as polyurethane or ethylvinylacetate, which operates toattenuate ground reaction forces as sole structure 30 contacts and iscompressed against the ground during walking, running, or otherambulatory activities.

Fluid-filled chamber 60 has the general configuration of a chamberformed from a polymer material that encloses a fluid (e.g., a gas,liquid, or gel). Although the fluid within chamber 60 may be referred toas pressurized, the fluid can be substantially at atmospheric pressure(i.e., zero gauge pressure) at ambient conditions. Chamber 60 can beincorporated within the midsole and lower areas of chamber 60 and can bepositioned adjacent and secured to outsole 70. Further, as shown inFIGS. 1-2, portions of sidewalls or peripheral surfaces 61 and 62 offluid-filled chamber 60 can be exposed to an exterior of footwear 10, atone or more locations between forefoot region 11 and heel region 13, andon lateral side 14, medial side 15, or both.

As examples, fluid-filled chamber 60 can incorporate various features orexhibit the general configurations of fluid-filled chambers disclosed inU.S. Pat. No. 7,556,846 to Dojan, et al.; U.S. Pat. No. 7,243,443 toSwigart; U.S. Pat. No. 6,571,490 to Tawney, et al.; U.S. Pat. No.7,131,218 to Schindler; U.S. Patent Application Publication 2008/0276490to Holt, et al.; and U.S. Patent Application Publication 2009/0151196 toSchindler, et al. A wide range of polymer materials can be utilized forforming chamber 60.

In selecting a material for chamber 60, the ability of the material toprevent the diffusion of the fluid contained by chamber 60 can beconsidered, as well as the engineering properties of the material (e.g.,tensile strength, stretch properties, fatigue characteristics, dynamicmodulus, and loss tangent). When formed from a polymer material, chamber60 can have a thickness of approximately 1.0 millimeter, but thethickness can range from 0.25 to 4.0 millimeters or more, for example,depending upon the specific polymer material utilized. Examples ofthermoplastic polymer materials that can be suitable for chamber 60include urethane, polyurethane, polyester, polyester polyurethane, andpolyether polyurethane. Various thermoset polymer materials can also beutilized for chamber 60. More specific examples of materials that can beutilized for chamber 60 include the various materials disclosed in anyof the following: (a) U.S. Pat. Nos. 4,183,156, 4,219,945, 4,936,029,and 5,042,176 to Rudy; (b) U.S. Pat. Nos. 5,713,141 and 5,952,065 toMitchell, et al.; and (c) U.S. Pat. Nos. 6,013,340, 6,082,025,6,127,026, 6,203,868, and 6,321,465 to Bonk, et al.

The fluid within chamber 60 can be pressurized to a common pressure. Insome configurations, chamber 60 can enclose fluids pressurized betweenzero and three-hundred-fifty kilopascals (i.e., approximately fifty-onepounds per square inch) or more. In addition to air and nitrogen, thefluid contained by chamber 60 can include octafluorapropane or be any ofthe gasses disclosed in U.S. Pat. No. 4,340,626 to Rudy, such ashexafluoroethane and sulfur hexafluoride, for example. Outsole 70 can besecured to lower surface regions of chamber 60 and can be formed from atextured, durable, and wear-resistant material (e.g., rubber) that formsthe ground-contacting portion of footwear 10. Various adhesives, thermalbonding techniques, or mechanical systems can be utilized to secureoutsole 70 to chamber 60.

When the foot is located within upper 20, midsole element 40, chamber60, and outsole 70 extend under the foot in order to attenuate groundreaction forces, provide traction, impart stability, and limit variousfoot motions. More particularly, the foamed polymer material of midsoleelement 40 and fluid-filled aspects of chamber 60 compress, flex orotherwise deform upon the application of forces from the foot toattenuate ground reaction forces. Outsole 70 also has a durable andwear-resistant configuration that imparts traction. Accordingly, thevarious elements of sole structure 30 operate cooperatively to providevarious advantages to footwear 10.

A variety of techniques can be utilized to manufacture sole structure30. As an example, a mold can be utilized to form midsole element 40 andembed fluid-filled chamber 60 within midsole element 40. Outsole 70 canthen be secured to midsole element 40 including fluid-filled chamber 60.

Example Fluid-Filled Chamber Configuration

Referring now to FIGS. 3-8, an additional configuration of afluid-filled chamber 310 is shown that generally include the aspects andpreferences discussed above along with potential configurations offluid-filled chamber 60 except as noted below. As shown in FIGS. 3, 4, 7and 8, fluid-filled chamber 310 is formed from a pair of opposing sheets312, 314, which can be high-frequency weldable sheets, such asradio-frequency (RF) weldable sheets. High-frequency weldable or RFweldable sheets can include any type of sheet that can be welded viahigh-frequency welding techniques including RF welding techniques, suchas a wide variety of polymer sheets that can be discretely heated totheir molding temperature ranges via the application of high-frequencywaves including radio waves and microwaves. These can include varioustypes of polymer sheets noted above along with chamber 60, such asmono-layer and multi-layer polymer sheets formed from polymers likeurethane, polyurethane, polyester, polyester polyurethane, and polyetherpolyurethane.

Fluid-filled chamber 310 includes an upper sheet 312 bonded to a lowersheet 314 by a perimeter weld 316 along a perimeter 322 of fluid-filledchamber 310. The upper sheet 312, lower sheet 314 and perimeter weld 316joining the sheets together define an internal chamber 318 containing afluid 320. The fluid 320 can include gases, such as air, nitrogen or amixture of gases. Further, as noted above for chamber 60, fluid 320 caninclude octafluorapropane or any of the gasses disclosed in U.S. Pat.No. 4,340,626 to Rudy, such as hexafluoroethane and sulfur hexafluoride,for example. As with chamber 60, fluid 320 can be pressurized to acommon pressure, such as a pressure substantially equal to atmosphericpressure (e.g., gauge pressure of about zero) to much higher positivepressures. In some configurations, chamber 310 can enclose fluidspressurized between zero and three-hundred-fifty kilopascals (i.e.,approximately fifty-one pounds per square inch) or more.

In the configuration shown in FIGS. 3-8, upper sheet 312 has a contouredsurface, such as a dish-like shape, lower sheet 314 is generally flat,and perimeter weld 316 is disposed along a lower lateral portion offluid-filled chamber 310. However, these shapes are shown as exampleconfigurations and it is understood that either or both of sheets 312and 314 can have relatively complex or simple contours and shapes.Further, it is understood that the shape of perimeter weld 316 can varyand can be relatively simple or complex as desired. In the configurationshown, perimeter weld 316 has a relatively simple oval shape. However,perimeter weld 316 can have a wide variety of complex shapes asappropriate for the desired fluid-filled chamber configuration.

Notably, perimeter weld 316 can be formed as a continuous, uninterruptedweld extending the length of the perimeter 322 of fluid-filled chamber310 at the intersection of sheets 312 and 314. In addition, perimeterweld 316 can be formed as a uniform weld having a generally constantcross-sectional area that lacks appendages, extensions or otherfeatures. In particular, perimeter weld 316 lacks an inflation channelor any appendages, extensions or features remaining from the formationof an inflation channel used for filling internal chamber 318 with fluid320 or created for filling internal chamber 318 with fluid as part of asecondary process.

As such, fluid-filled chamber 310 maintains a simple profile lackingunnecessary features, including unnecessary features along its perimeterweld, that can create superfluous material or stress concentrationsduring use. Further, fluid-filled chamber 310 can provide additionaladvantages, such as providing a profile that can allow it to beinstalled easily in a sole structure of an article of footwear withoutinterfering with other structures during assembly or during use. Inparticular, it can provide a chamber 310 without features along theperimeter weld that can inhibit the flow of foam or other mold materialsplaced proximate the fluid-filled chamber during its installation into asole structure and the subsequent manufacture of an article of footwear(i.e., features such as an extraneous inflation channel or otherappendage or extension related to formation of the chamber).

In addition, fluid-filled chamber 310 can provide advantages related toits manufacture. For example, it can permit chamber 310 to be formed viaa single stage manufacturing process using a single apparatus to (a)weld sheets 312 and 314 to each other, (b) fill chamber 310 with fluid320, and (c) seal the fluid-filled chamber. In comparison, prior artfluid-filled chambers formed from polymer sheets are formed viamulti-stage manufacturing processes using multiple manufacturingdevices, stations and/or stages to weld the sheets to each other, fillthe chamber with fluid and seal the chamber.

Further, some prior art chambers are initially formed from sheets ofmaterial with an inflation channel extending from the perimeter weld orbeing formed and remaining elsewhere on the chamber. The prior artchambers are subsequently filled with fluid and sealed after formationof the chamber using separate equipment than equipment that formed thechamber and as part of a separate process from the chamber-formingprocess. If the inflation channel is subsequently removed in whole or inpart from the prior art chamber after inflation, it is done so after thechamber is filled and sealed, and the perimeter weld has a differingcross-section at the location of the inflation channel (i.e., theperimeter weld is non-uniform). FIGS. 9-14 show an example welderconfiguration that can form fluid-filled chamber 310 with a continuous,uniform perimeter weld without an inflation channel at the perimeterweld or elsewhere on the chamber, and that can form fluid-filled chamber310 via a single stage process on a single apparatus.

Example Welder Apparatus

Referring now to FIGS. 9-14, an example high-frequency welder apparatus910 is shown for forming a pressurized fluid-filled chamber that lacksan inflation channel from a two or more polymer sheets and to do so in asingle stage that includes forming, filling and sealing the chamber. Asshown in FIGS. 9 and 10, welder apparatus 910 includes a cavity weldsupport 932 (shown as an upper support, for example), a core weldsupport 934 (shown as a lower support, for example) disposed oppositecavity weld support 932, and a movable gate valve 936 formed in one ofthe weld supports (shown formed in the core weld support, for example).An inflation tube 938 is shown disposed between the weld supports inFIG. 10.

FIG. 10 shows welder apparatus 910 in an open configuration near thebeginning of a single stage fluid-filled chamber welding/filling/sealingprocess. As such, FIG. 10 includes a pair of polymer sheets 912, 914 ofhigh-frequency weldable polymer material disposed between the weldsupports including an upper sheet 912 and an opposite lower sheet 914.The upper and lower sheets 912, 914 sandwich an inflation end 940 ofinflation tube 938 located between edge portions of the sheets at aposition proximate movable gate valve 936. The cavity weld support 932and/or the core weld support 934 can form an extended external inflationchannel 991 that can allow extended perimeter portions of the sheets toseal a length of inflation tube 938 during inflation and welding. Thiscan provide an improved seal during processing by enabling a large sealregion around the inflation tube. Early in the process, cavity and coreweld supports 932 and 934 move toward each other to retain upper andlower sheets 912 and 914 in a desired position as shown in FIG. 11.

In the configuration shown in FIGS. 9-14, cavity weld support 932 has acontoured cavity surface 942 that includes a recessed central portion944 and a raised perimeter weld portion 946 disposed about a centralregion. Likewise, core weld support 934 has a core surface 948 facingcontoured cavity surface 942. Core surface 948 is generally flat in theconfiguration of FIGS. 9-14, but it can also be contoured as appropriatefor desired fluid-filled chamber shapes and configurations. Core surface948 also has a central portion 950 and a perimeter weld portion 952disposed about the central portion.

Cavity raised perimeter weld portion 946 and core perimeter weld portion952 are configured to mate with one another (or otherwise complementeach other, such as by applying opposing forces) when the welderapparatus 910 is in the closed position, such as is shown in FIGS.11-13, during which upper and lower sheets 912 and 914 are sandwichedtherebetween. In the closed configuration, the upper and lower sheets912 and 914 are pressed against each other with sufficient force to forma seal 954 along matching perimeter portions of upper and lower sheets912 and 914 that prevents fluid from flowing between the sheets at theseal.

As shown in FIGS. 11 and 12, gate valve 936 is disposed proximate coreperimeter weld portion 952, seal 954 and inflation end 940 of inflationtube 938. Gate valve 936 is configured to retract away from core surface948, core perimeter weld portion 952, and polymer sheets seal 954 at adiscrete gate region 956 of core perimeter weld portion 952, which canunseal the polymer sheets at that location. In addition, inflation tube938 is configured to deliver pressurized fluid, such as a pressurizedgas noted above for use with pressurized fluid-filled chambers (like airor an inert gas like nitrogen), to an exit port on its inflation end 940at a location between the polymer sheets that is proximate gate region956 from which gate valve 936 has retracted. As illustrated in FIG. 12,the combination of gate valve 936 being retracted from gate region 956and pressurized fluid being delivered to inflation end 940 permits atemporary inflation channel 960 to be formed between the polymer sheetsand through a discrete portion of seal 954, which allows pressurizedfluid from inflation tube 938 to flow into an interior void 962 formedbetween the polymer sheets within seal 954.

The entry of pressurized fluid into interior void 962 inflates thechamber and raises a corresponding central portion 964 of upper sheet912 against recessed central portion 944 of contoured cavity surface942. When interior void 962 has been inflated sufficiently, gate valve936 begins to close while pressurized fluid continues to be provided totemporary inflation channel 960. When gate valve 936 is completelyclosed, it stops the flow of fluid into interior void 962, closestemporary inflation channel 960, and reestablishes seal 954 as acomplete seal around interior void 962.

At this point (shown in FIG. 13), high frequency energy, such as radiofrequency (RF) waves (e.g., microwaves) are directed between raisedperimeter weld portion 946 and core perimeter weld portion 952 throughportions of polymer sheets 912 and 914 disposed at seal 954 for a shortweld period, as is known in the art of RF welding. The portions ofpolymer sheets 912 and 914 disposed at seal 954 are melted and bonded toeach other during this period to form a perimeter weld 916 along aperimeter of interior void 962, which seals the chamber and forms apressurized fluid-filled chamber. If desired, the cavity and core weldsupports 932 and 934 can be retained in their closed position for ashort cooling period after completion of the welding process, such asfor a few seconds. The use of a cooling period can be beneficial forhelping to retain the sealed, welded fluid-filled chamber bond, shapeand configuration, such as for configurations involving high-pressurefluids, thin polymer sheets, or complex weld shapes.

Cavity and core weld supports 932 and 934 are separated thereafter topermit removal of the pressurized fluid-filled chamber 970 that wasformed by the process. As shown in FIG. 14, the formation offluid-filled chamber 970 using welder apparatus 910 as describedprovides a pressurized fluid-filled chamber that lacks an inflationchannel or any appendages, extensions or features along perimeter weld916. This is due to (a) the use of temporary inflation channel 960 tofill interior void 962 prior to welding, (b) the use of welding clampsto maintain the fluid seal thereafter through completion of the weldingprocess, and (c) the gate design that eliminates the temporary inflationchannel once the internal chamber has been filled, so there is noremaining inflation channel or appendages and no need for additionalfilling and sealing operations for the fluid-filled chamber.

Example Method

FIGS. 15 and 16A-16B show example steps for a method 1400 that can beused to form a fluid-filled chamber lacking an inflation channel andhaving a uniform sealing weld. The method described can be used withexample weld apparatus 910 discussed above and can form the examplefluid-filled chambers 310 and 970 discussed above, but can also be usedwith other weld devices and to form fluid-filled chambers having avariety of configurations. As shown in FIG. 15, method 1400 can includea step 1410 of placing a pair of polymer sheets in an opposingarrangement for forming a fluid-filled chamber and a step 1412 ofpressing opposing perimeter weld portions of the polymer sheets againsteach other to form a fluid seal (i.e., an airtight seal) along aperimeter region of the fluid-filled chamber. Method 1400 can furtherinclude a step 1414 of providing a flow of pressurized air between theopposing sheets to a temporary inflation region of the perimeter weldportions and a step 1416 of unsealing the temporary inflation region ofthe perimeter weld portions to permit the flow of pressurized airthrough an inflation gap formed between the opposing sheets in thetemporary inflation region until a desired fluid pressure is reached.Method 1400 can further include a step 1418 of, while maintaining thedesired fluid pressure, welding the perimeter weld portions of thesheets to each other including the temporary inflation region to form anuninterrupted perimeter weld around the fluid-filled chamber withouthaving an inflation channel formed in the perimeter weld.

Referring now to FIG. 16A, step 1410 of method 1400 can include a step1510 of placing perimeter weld portions of the sheets proximate eachother such that the perimeter weld portions outline an interior void forthe fluid-filled chamber. In addition, step 1410 can further include astep 1512 of placing an inflation channel between the polymer sheetsextending from an exterior region beyond the polymer sheets toward aninflation region of the perimeter weld portions.

Referring now to FIG. 16B, step 1416 of method 1400 can include step1612 of unpressing the inflation region of the sealed perimeter weldportions to permit a gap to form between the opposed polymer sheets atthe inflation region. In addition, step 1416 can further include step1614 of encouraging pressurized fluid to flow through the gap formed atthe unsealed inflation region and into an interior void of thefluid-filled chamber disposed between the polymer sheets and within theperimeter weld portions.

Another Example Welder Apparatus

Referring now to FIGS. 17-21, another example high-frequency welderapparatus 1710 is shown for forming a pressurized fluid-filled chamberthat lacks an inflation channel from two or more polymer sheets and todo so in a single stage that includes forming, filling and sealing thechamber. High-frequency welder apparatus 1710 generally includes theaspects and preferences discussed above with high-frequency welderapparatus 910, except as discussed below. As shown in FIG. 17, welderapparatus 1710 includes a cavity weld support 1732 (shown as an uppersupport, for example), a core weld support 1734 (shown as a lowersupport, for example) disposed opposite cavity weld support 1732, amovable gate valve 1736 formed in one of the weld supports (shown formedin the core weld support, for example), and an inflation tube 1738disposed between the weld supports.

FIG. 17 shows welder apparatus 1710 in an open configuration near thebeginning of a single stage fluid-filled chamber welding/filling/sealingprocess. As such, FIG. 17 includes an a pair of polymer sheets 1712,1714 of high-frequency weldable polymer material disposed between theweld supports including an upper sheet 1712 and an opposite lower sheet1714. The upper and lower sheets 1712, 1714 sandwich an inflation end1740 of an inflation tube 1738 located between edge portions of thesheets at a position proximate movable gate valve 1736. Early in theprocess, cavity and core weld supports 1732 and 1734 move toward eachother to retain upper and lower sheets 1712 and 1714 in a desiredposition as shown in FIG. 18. Welder apparatus 1710 also includes anextended external inflation channel 1791, which is similar to inflationchannel 991, that can allow extended perimeter portions of the sheets toseal a length of inflation tube 1738 during inflation and welding.

In the configuration shown in FIGS. 17-21, cavity weld support 1732 hasa contoured cavity surface 1742 that includes a recessed central portion1744 and a raised perimeter weld portion 1746 disposed about a centralregion. Likewise, core weld support 1734 also has a contoured coresurface 1748 facing contoured cavity surface 1742 that also includes arecessed central portion 1750 and a raised perimeter weld portion 1752disposed about the central portion. Thus, both sides of weld apparatus1710 include contoured support surfaces for forming a fluid-filledchamber having contoured surfaces on both primary surfaces. In addition,cavity weld support 1732 includes optional vacuum lines 1774, which canhelp retain upper sheet 1712 in a desired position against cavitysurface 1742 during welding, inflating and sealing operations and allowany trapped air between the upper sheet 1712 and mold cavity surface1742 to be vented. Of course, it is understood that vacuum lines couldalso be included in core weld support 1734 as desired. It is furtherunderstood that weld supports 1732 and 1734 could be oriented in variousways, such as both weld supports being oriented vertically, at variousangles, or in a reverse configuration with the core weld support 1734being disposed above the cavity weld support 1732.

Cavity raised perimeter weld portion 1746 and core raised perimeter weldportion 1752 are configured to mate with one another (or otherwisecomplement each other, such as by applying opposing forces) when thewelder apparatus 1710 is in the closed position, such as is shown inFIGS. 10-12, during which upper and lower sheets 1712 and 1714 aresandwiched therebetween. In the closed configuration, the upper andlower sheets 1712 and 1714 are pressed against each other withsufficient force to form a seal 1754 along matching perimeter portionsof upper and lower sheets 1712 and 1714 that prevents fluid from flowingbetween the sheets at the seal.

As shown in FIGS. 18 and 19, gate valve 1736 is disposed proximateraised perimeter weld portion 1752, seal 1754 and an inflation end 1740of inflation tube 1738. Gate valve 1736 is configured to retract awayfrom contoured core surface 1748, core perimeter weld portion 1752, andseal 1754 at a discrete gate region 1756 of raised perimeter weldportion 1752, which can unseal the polymer sheets at that location. Inaddition, inflation tube 1738 is configured to deliver pressurizedfluid, such as a pressurized gas noted above for use with pressurizedfluid-filled chambers like air or an inert gas like nitrogen, to an exitport on its inflation end 1740 at a location between the polymer sheetsthat is proximate gate region 1756 from which gate valve 1736 hasretracted. As illustrated in FIG. 19, the combination of gate valve 1736being retracted from gate region 1756 and pressurized fluid beingdelivered to inflation end 1740 permits a temporary inflation channel1760 to be formed between the polymer sheets and through a discreteportion of seal 1754, which allows pressurized fluid from inflation tube1738 to flow into an interior void 1762 formed between the polymersheets within seal 1754.

The entry of pressurized fluid into interior void 1762 bilaterallyinflates the chamber and raises a corresponding central portion 1764 ofupper sheet 1712 against recessed central portion 1744 of contouredcavity surface 1742 and depresses a corresponding central portion 1765of lower sheet 1714 against recessed central portion 1750 of contouredcore surface 1748. When interior void 1762 has been inflatedsufficiently, gate valve 1736 begins to close while pressurized fluidcontinues to be provided to temporary inflation channel 1760. When gatevalve 1736 is completely closed, it stops the flow of fluid intointerior void 1762, closes temporary inflation channel 1760, andreestablishes seal 1754 as a complete seal around interior void 1762.

At this point (shown in FIG. 20), high frequency energy, such as radiofrequency (RF) waves (e.g., microwaves) are directed between raisedperimeter weld portion 1746 and raised perimeter weld portion 1752through portions of polymer sheets 1712 and 1714 disposed at seal 1754for a short weld period, as is known in the art of RF welding. Theportions of polymer sheets 1712 and 1714 disposed at seal 1754 aremelted and bonded to each other during this period to form a perimeterweld 1716 along a perimeter of interior void 1762, which seals thechamber and forms a pressurized fluid-filled chamber. If desired, thecavity and core weld portions 1732 and 1734 can be retained in theirclosed position for a short cooling period after completion of thewelding process, such as for a few seconds. The use of a cooling periodcan be beneficial for helping to retain the sealed, welded fluid-filledchamber bond, shape and configuration, such as for configurationsinvolving high-pressure fluids, thin polymer sheets, or complex weldshapes.

Cavity and core weld portions 1732 and 1734 are separated thereafter topermit removal of the pressurized fluid-filled chamber 1770 that wasformed by the process. As shown in FIG. 21, the formation offluid-filled chamber 1770 using weld apparatus 1710 as describedprovides a pressurized, fluid-filled chamber that lacks an inflationchannel and any appendages along perimeter weld. This is due to (a) thenovel use of a temporary inflation channel to fill the interior void1760 prior to welding, (b) the use of welding clamps to maintain thefluid seal thereafter through completion of the welding process, and (c)the gate design that eliminates the temporary inflation channel once theinternal chamber has been filled, so there is no remaining inflationchannel or appendages and no need for additional filling and sealingoperations for the fluid-filled chamber.

An Additional Welder Apparatus

Referring now to FIGS. 22-23, yet another example high-frequency welderapparatus 2210 is shown for forming a pressurized fluid-filled chamberthat lacks an inflation channel from a two or more polymer sheets and todo so in a single stage that includes forming, filling and sealing thechamber. High-frequency welder apparatus 2210 generally includes theaspects and preferences discussed above with high-frequency welderapparatus 1710, except as discussed below. In particular, high-frequencywelder apparatus 2210 is generally a dual mold version of high-frequencywelder apparatus 1710 that can simultaneously form, fill and seal twofluid-filled chambers. As such, cavity weld support 2232 has a contouredcavity surface 2242 having two recessed central portions 2244A, 2244Band two raised perimeter weld portions 2246A, 2246B—a set of eachcorresponding to each of the fluid-filled chambers. Similarly, core weldsupport 2234 has a contoured core surface 2248 having two recessedcentral portions 2250A, 2250B and two raised perimeter weld portions2252A, 2252B. Only one set of the recessed central portions and raisedperimeter weld portions for each of the cavity and core weld supports isshown in FIG. 22.

However, FIG. 23 shows portions of both recessed central portions 2250Aand 2250B and both raised perimeter weld portions 2252A and 2252B forthe core weld support 2234. It is understood that many otherconfigurations can be used for high-frequency welder apparatus 2210,such as multi-mold configurations have more than two mold cavitiesand/or having mold cavities in varying configurations. FIG. 23 furtherillustrates a mixed mold configuration for forming fluid-filled chambershaving differing configurations. For instance, raised perimeter weldportion 2252A outlines a fluid-filled chamber having a generally roundedrectangular perimeter shape, whereas raised perimeter weld portion 2252Boutlines a fluid-filled chamber having a generally circular or ovalperimeter shape.

As with previous configurations, high-frequency welder apparatus 2110also makes use of angled gate valves 2236A and 2236B. Angled gate valvescan be beneficial for helping to guide a desired shape and path for thetemporary inflation channel (e.g., temporary inflation channels 960 and1760 shown in FIGS. 11 and 19) and ensuring that the perimeter weldincludes as much as possible of the temporary inflation channel when itis formed. High-frequency welder apparatus 2210, however, makes use of asingle inflation tube 2238 for providing pressurized fluid to multipleinternal chambers for forming multiple fluid-filled chambers.

Along with this efficient arrangement for providing pressurized fluidfrom a single inflation tube, core weld support 2234 includes inflationcanals 2276 formed in core surface 2248, which encourage a desiredshape, orientation and configuration for the temporary inflationchannels (not shown in FIGS. 21 and 22) when filling the correspondingfluid-filled chambers. It is understood that matching inflation canalscan also be formed in the cavity mold support 2232 as desired, eitheralone or in combination with core inflation canals 2276, and thatsimilar canals can be formed in other high-frequency welder devicesincluding those discussed previously.

Another Example Fluid-Filled Chamber Configuration and Example WeldingApparatus

FIG. 24 depicts another fluid-filled chamber 2410 having a generalconfiguration suitable for incorporation into a strap of a sportscontainer for carrying sports equipment, such as a golf bag for carryinggolf clubs, or a hockey bag for carrying hockey equipment. Conceptsassociated with fluid-filled chamber 2410 can also be applied to otherpersonal carriers, such as backpacks or luggage, or to any of thevariety of products discussed above with respect to fluid-filled chamber310. Accordingly, the concepts disclosed herein can be applied to a widevariety of products.

Fluid-filled chamber 2410 generally includes aspects and preferencesdiscussed above regarding fluid-filled chambers 60 and 310, except asnoted below. As shown in FIG. 24, fluid-filled chamber 2410 is formedfrom a pair of opposing sheets which can be high-frequency weldablesheets such as RF weldable sheets. More particularly, fluid-filledchamber 2410 includes an upper sheet 2412 joined to a lower sheet 2414by a continuous, uninterrupted perimeter weld 2416 along a perimeter offluid-filled chamber 2410. Fluid-filled chamber 2410 additionallyincludes a plurality of internal welds 2418 spaced inward from theperimeter of chamber 2410. Upper sheet 2412, lower sheet 2414, perimeterweld 2416, and internal welds 2418 together define fluid-filled chamber2410.

As shown in FIG. 24, fluid-filled chamber 2410 has a generally elongateconfiguration with a width and a length that is greater than the widthby a factor of two. In various configurations, the length of theelongate configuration may be greater than the width of the elongateconfiguration by a factor of two, three, five, or more. The elongateconfiguration of fluid-filled chamber 2410 can facilitate its use in thestrap of the sports container, to enhance the cushioning the strapprovides when resting against the body of a wearer.

FIG. 25 shows an example high-frequency welder apparatus 2510 forforming fluid-filled chamber 2410. Welder apparatus 2510 generallyincludes aspects and preferences noted above regarding welderapparatuses 910, 1710, and 2210, except as noted below. As depicted,welder apparatus 2510 includes a cavity weld support 2532, a core weldsupport 2534 disposed opposite cavity weld support 2532, and a movablegate valve 2536 (shown formed in core weld support 2534).

Cavity weld support 2532 has a contoured cavity surface 2542 thatincludes a recessed central portion 2544, a raised perimeter weldportion 2546 disposed about a central region, and a plurality ofinternal weld portions 2548. As depicted, core weld support 2534 has agenerally flat surface facing contoured cavity surface 2542. (In otherconfigurations, the core surface can also be contoured as appropriatefor the desired shape of fluid-filled chamber 2410.)

The surface of core weld support 2534 has a central portion and aperimeter weld portion disposed about the central portion. When welderapparatus 2510 is in the closed position, raised perimeter weld portion2546 of cavity weld support 2532 is configured to mate with theperimeter weld portion of the surface of core weld support 2534. Thesurface of core weld support 2534 additionally has an internal weldportion 2548 in the central portion of the core surface. When welderapparatus 2510 is in the closed position, perimeter weld portions 2548of cavity weld support 2532 are configured to mate with perimeter weldportion 2548 of core weld support 2534. The cavity weld support 2532and/or the core weld support 2534 can form an extended externalinflation channel 2591 that can allow extended perimeter portions of thesheets to seal a length of an inflation tube during inflation andwelding.

When welder apparatus 2510 is closed, two polymer sheets may be pressedagainst each other by raised perimeter weld portion 2546 of cavity weldsupport 2532 and the perimeter weld portion of the surface of core weldsupport 2534 with sufficient force to form a seal along perimeterportions of the two polymer sheets. Similarly, the polymer sheets may bepressed against each other by perimeter weld portions 2548 of cavityweld support 2532 and perimeter weld portion 2548 of core weld support2534 with sufficient force to form a plurality of interior seals atinternal portions of the two polymer sheets.

Subsequently, gate valve 2536 may retract away from the core surface andunseal the polymer sheets at a location proximate to gate valve 2536,and an inflation tube within external inflation channel 2591 may delivera pressurized fluid to the same location, the combination of which mayform a temporary inflation channel. The pressurized fluid may flowthrough the temporary inflation channel to inflate the chamber. Whensufficient inflation has been achieved, gate valve 2536 may close,stopping the flow of pressurized fluid and reestablishing the seal as acomplete seal. High frequency energy (e.g. RF waves) may then bedirected between mating portions of cavity weld support 2532 and coreweld support 2534, causing the polymer sheets to melt and bond with eachother to at the perimeter seal and the interior seals to form aperimeter weld and a plurality of internal welds. Cavity weld support2532 and core weld support 2534 may thereafter be separated, andfluid-filled chamber 2410 with continuous, uninterrupted perimeter weld2416 may be removed.

The invention is disclosed above and in the accompanying figures withreference to a variety of configurations. The purpose served by thedisclosure, however, is to provide an example of the various featuresand concepts related to the invention, not to limit the scope of theinvention. One skilled in the relevant art will recognize that numerousvariations and modifications can be made to the configurations describedabove without departing from the scope of the present invention, asdefined by the appended claims.

What is claimed is:
 1. A mold for forming a fluid-filled chamber formedfrom a first sheet and a second sheet, the mold comprising: a first moldhalf having a first weld portion; a second mold half having a secondweld portion, the second weld portion aligned with the first weldportion to create a perimeter weld between the first sheet and thesecond sheet of the fluid-filled chamber when the first mold half andthe second mold half are moved from an open state to a closed state; anda gate valve associated with one of the first mold half and the secondmold half and including a weld portion aligned with the first weldportion and the second weld portion, the gate valve moveable relative tothe one of the first mold half and the second mold half to create aninflation channel between the first sheet and the second sheet at theperimeter weld by separating one of the first sheet and the second sheetfrom the other of the first sheet and the second sheet.
 2. The mold ofclaim 1, further comprising an inflation tube operable to providepressurized fluid between the first sheet and the second sheet.
 3. Themold of claim 2, wherein the inflation tube is positioned adjacent toand is in fluid communication with the inflation channel to permitpressurized fluid from the inflation tube to enter an area between thefirst sheet and the second sheet.
 4. The mold of claim 2, wherein theinflation tube is positioned adjacent to and is in fluid communicationwith the inflation channel when the first mold half and the second moldhalf are in the closed state to permit pressurized fluid from theinflation tube to enter an area between the first sheet and the secondsheet.
 5. The mold of claim 1, wherein the first mold half and thesecond mold half are movable from the open state to the closed state toform the perimeter weld by applying pressure to the first sheet and thesecond sheet.
 6. The mold of claim 1, wherein the gate valve is operableto move relative to the one of the first mold half and the second moldhalf when the first mold half and the second mold half are in the closedstate to separate the one of the first sheet and the second sheet fromthe other of the first sheet and the second sheet.
 7. The mold of claim1, wherein the gate valve is operable to move away from the other of thefirst mold half and the second mold half when the first mold half andthe second mold half are in the closed state to separate the one of thefirst sheet and the second sheet from the other of the first sheet andthe second sheet.
 8. The mold of claim 1, wherein the gate valve isoperable to move toward the other of the first mold half and the secondmold half to close the inflation channel by reattaching the first sheetand the second sheet at the inflation channel.
 9. The mold of claim 1,wherein the other of the first mold half and the second mold halfincludes a cavity operable to receive the other of the first sheet andthe second sheet upon inflation of the fluid-filled chamber.
 10. Themold of claim 1, wherein the other of the first mold half and the secondmold half includes at least one vacuum port operable to draw the otherof the first sheet and the second sheet against a surface of the otherof the first mold half and the second mold half.
 11. A mold for forminga fluid-filled chamber formed from a first sheet and a second sheet, themold comprising: a first mold half having a first weld portion; a secondmold half having a second weld portion, the second weld portion alignedwith the first weld portion to create a perimeter weld between the firstsheet and the second sheet of the fluid-filled chamber when the firstmold half and the second mold half are moved from an open state to aclosed state; and a gate valve associated with one of the first moldhalf and the second mold half and including a weld portion aligned withthe first weld portion and the second weld portion, the gate valveoperable in a first state to create an inflation channel by separatingthe first sheet and the second sheet at the perimeter weld when thefirst mold half and the second mold half are in the closed state andoperable in a second state to close the inflation channel by reattachingthe first sheet and the second sheet at the perimeter weld when thefirst mold half and the second mold half are in the closed state. 12.The mold of claim 11, further comprising an inflation tube operable toprovide pressurized fluid between the first sheet and the second sheet.13. The mold of claim 12, wherein the inflation tube is positionedadjacent to and is in fluid communication with the inflation channel topermit pressurized fluid from the inflation tube to enter an areabetween the first sheet and the second sheet.
 14. The mold of claim 12,wherein the inflation tube is positioned adjacent to and is in fluidcommunication with the inflation channel when the first mold half andthe second mold half are in the closed state to permit pressurized fluidfrom the inflation tube to enter an area between the first sheet and thesecond sheet.
 15. The mold of claim 11, wherein the first mold half andthe second mold half are movable from the open state to the closed stateto form the perimeter weld by applying pressure to the first sheet andthe second sheet.
 16. The mold of claim 11, wherein the gate valve isoperable to move away from the other of the first mold half and thesecond mold half when the first mold half and the second mold half arein the closed state to separate one of the first sheet and the secondsheet from the other of the first sheet and the second sheet.
 17. Themold of claim 11, wherein the gate valve is operable to move toward theother of the first mold half and the second mold half to close theinflation channel by reattaching the first sheet and the second sheet atthe inflation channel.
 18. The mold of claim 11, wherein the other ofthe first mold half and the second mold half includes a first cavityoperable to receive one of the first sheet and the second sheet uponinflation of the fluid-filled chamber.
 19. The mold of claim 18, whereinthe one of the first mold half and the second mold half includes asecond cavity operable to receive the other of the first sheet and thesecond sheet upon inflation of the fluid-filled chamber.
 20. The mold ofclaim 11, wherein the other of the first mold half and the second moldhalf includes at least one vacuum port operable to draw one of the firstsheet and the second sheet against a surface of the other of the firstmold half and the second mold half.